Field of the Invention
The present invention relates to a depth limiting device used for a drill and a drill that includes the depth limiting device.
Discussion of the Related Art
A drill is a tool used for drilling a hole in a subject. For example, a bone drill can be used for drilling a hole in a bone in a surgery. When a drill is used for drilling a hole in a bone, a surgical doctor holds the drill and pressurizes for drilling. After the drill breaks through the bone substance completely, the electric drill falls through, and it is often difficult and even sometime impossible for the surgical doctor to stop pressurizing at the same time, so the drill may drill forwards continuously. In the drilling process, damages of tissues may be resulted; and if vessels and nerves existing in the heading direction of the drill are damaged, serious consequences may be resulted. In addition, measurement of the depth of the drilling hole is also needed for determination of a suitable screw after the hole drilling process is finished. Existing drills, however, only have a hole drilling function, so the surgical doctor needs to measure the drilling hole by inserting a depth measuring device in the drilled hole. There is a need for improved drill that will reduce the damages to tissues, vessels, and nerves during the drilling process.